Amazon, which earlier patented a drone that would fragment in mid-air in event of malfunction to minimize potential damage to schoolkids and others, has just acknowledged in a new patent that delivery drones may fly into buildings.

In a patent granted this week for an “Unmanned aerial vehicle protective frame configuration,” the Seattle e-commerce giant notes a risk that accompanies its effort to get its products to customers via drones, also known as UAVs.

“For example, if the UAV is traveling horizontally and collides with a foreign object (e.g., wall, building), the impact between the UAV and the foreign object will be with the perimeter protective barrier, rather than a propeller,” the patent said.

Whether the public will become accustomed to having goods-laden drones passing overhead and perhaps dropping parts or flying into large solid objects remains to be seen. But Amazon, keenly focused on automation and cheap, efficient product delivery, has obtained dozens of drone-related patents in recent years.

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The new patent for a drone with a protective frame also outlines possible other propulsion systems, beside propellers, for UAVs. Systems could include “fans, jets, turbojets, turbo fans, jet engines, internal combustion engines, and the like,” according to the patent.

Ethan Baron is a business reporter at The Mercury News, and a native of Silicon Valley before it was Silicon Valley. Baron has worked as a reporter, columnist, editor and photographer in newspapers and magazines for 25 years, covering business, politics, social issues, crime, the environment, outdoor sports, war and humanitarian crises.

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